MG53 protects umbilical cord mesenchymal stem cells from oxidative damage

Objective To establish a H2O2oxidative damage model of human umbilical cord mesenchymal stem cells (hUC-MSCs) , and to investigate the protective effects of recombinant human MG53 protein (rhMG53) on hUC-MSCs oxidative damage. Methods hUC-MSCs were isolated from human umbilical cord tissue collected from healthy donors, and the cell phenotype was determined by flow cytometry; the H2O2-treated P3 hUC-MSCs were evaluated by CCK-8 method. The cells were allocated into four groups: normal control group (NC group) , rhMG53 group, H2O2group and H2O2+ rhMG53 group. The effect of rhMG53 on hUC-MSC proliferation, migration, senescence, cell cycle and apoptosis was respectively detected by CCK-8 assay, Transwell assay, flow cytometry andβ-galactosidase staining. Cell proliferation was analyzed by the variance analysis of factorial design, and the single factor variance analysis was used to compare the differences between groups. Results The P3 hUC-MSCs were adherent and spindle shaped, and expressed mesenchymal stem cell markers CD44, CD133, HLA-ABC, with low expression of CD34 and CD45. H2O2inhibitedhUC-MSC growth in a concentration and time-dependent manner.When hUC-MSCs were treated with 200μmol/L H2O2for 16 h, the proliferation (0.994±0.011vs1.331±0.014), migration (8.15﹪±2.47﹪ vs33.34﹪±3.62﹪) and percentage of cells in S phase (29.67﹪±3.69﹪ vs34.3﹪3±4.25﹪) decreased, while the proportion of senescent cells (44.07﹪±5.26﹪ vs5.7﹪±1.42﹪) and apoptosis (52.63﹪±5.76﹪ vs4.65﹪±1.23﹪) significantly increased in the H2O2group compared with the NC group. The proliferation (1.509±0.086vs1.331±0.014) and migration (52.13﹪±5.46﹪ vs33.34﹪±3.62﹪) of cells in the rhMG53 group increased significantly. The proportion of cells in S phase (35.27﹪±4.79﹪ vs34.33﹪±4.25﹪) was similar (P> 0.05) , and the proportion of senescent cells (3.92﹪±1.31﹪ vs5.7﹪±1.42﹪) and apoptosis (3.96﹪±1.06﹪ vs4.65±1.23﹪) was significantly decreased in the rhMG53 group (P< 0.05) . Compared with the H2O2group, thecell proliferation (1.252±0.056vs0.994±0.011) , migration ability (18.93﹪±3.12﹪ vs8.15﹪±2.47﹪) and the proportion of cells in S phase (34.84﹪±3.45﹪ vs29.67﹪±3.69﹪) of H2O2+ rhMG53 group was significantly increased, the proportion of senescent cells (17.89﹪±2.64﹪ vs44.07﹪±5.26﹪) and apoptosis (4.65﹪±1.23﹪ vs17.63﹪±2.56﹪) was significantly decreased (P < 0.05) . Key words: Phosphoproteins; Umbilical cord; Mesenchymal stem cells; Wounds and injuries; Protection